Abstract: A blower comprising an annular wall (2) formed to be spaced from blade tips of a fan (1), the annular wall having slits (6) formed at a portion opposed to the blade tips to establish communication between inner and outer peripheral portions of the annular wall, so that air is sucked into the inner peripheral portion of the annular wall through the slits as the fan rotates, characterized in that the width w of a gap of the slit is changed in radial and circumferential directions thereof, whereby the quantity of air flowing into the inner peripheral portion of the annular wall through the slits is made substantially equal over the entire circumference. By this configuration, leakage vortexes flowing from the pressure side to the suction side at the blade tips are restrained, and the P-Q characteristics are improved. At the same time, noise produced in the annular wall having slits can be restrained, so that a low-noise blower can be realized.

Abstract: The present apparatus provides a blower that improves the P-Q characteristic and reduces noise. The apparatus is a blower that sucks air inside through slits (6) provided in an annular wall (2), wherein the blade thickness near a blade end s is progressively reduced toward the front end, and the location F of the maximum thickness gradually moves back toward a blade trailing edge side u2 so as to make the blade advance angle near the front end larger than in other locations. In addition, the width of a slit is made wider in sections near a spacer than in other sections. Alternatively, notches are provided in the outer perimeter of annular plates near the spacers so as to reduce the radial length of the annular plates. This arrangement improves the P-Q characteristic and reduces noise.

Abstract: An inexpensive bearing unit having a high rotational accuracy and a high reliability is provided for use in information and video-acoustic equipments. In the case of an oil-impregnated sintered bearing (1) in which an inner surface (2) sliding together with a shaft is formed on the bearing body (1) made of a porous sintered alloy, a plurality of concavities (4) are transferred to a tapered portion of the bearing inner surface (2) by forming a part or the whole of the inner surface (2) into a tapered shape or a tapered-like shape at the time of molding a green compact of the sintered alloy and press-fitting a pin (5) formed with protrusions (6) in the subsequent process and moreover, concavities (7) in which the shaft sliding surface is closed are formed by sizing the tapered portion straight at the time of sizing. Because the concavities (7) making a superior dynamic-pressure effect can be formed in a simple process, it is possible to provide an inexpensive bearing unit having a high rotational accuracy.

Abstract: A small motor for use in an information-communication appratus, an audio-visual apparatus or the like, and a motor for use in a portable pager and a portable telephone or the like for generating vibrations to be transmitted to a human body, the motors being efficient, small and thin in size, and having a high degree of freedom when mounted on an apparatus. To realize the motor as described above, K pieces of (K indicating any integer greater than one) magnetic units (4a, 4b, 4c) having N and S poles magnetized alternately are mounted on a rotor in a circumferential direction, and K magnetic units are axially stacked in K stages and integrally retained on a shaft (6), and this rotor is rotatably supported on a pair of bearings (9a, 9b). Cores (1a, 1b, 1c) each have a salient pole (7a, 7b, 7c) wound around with coils (3a, 3b, 3c) in K stages so as to correspond to each of the magnetic units.